HDP-CVD deposition of low dielectric constant amorphous carbon film

• US 6,423,384 B1
• Filed: 06/25/1999
• Issued: 07/23/2002
• Est. Priority Date: 06/25/1999
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Khazeni, Kasra, Tzou, Eugene, Tan, Zhengquan
• Primary Examiner(s): CHEN, BRET P
• Application Number:
  US09/339,888
• Time in Patent Office: 1,124 Days
• Field of Search: 427/577, 427/249.1, 427/249.7, 427/376.1, 427/162
• US Class Current: 427/577
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/3146 Carbon layers, e.g. diamond-like layers

Abstract

The present invention generally provides a method for depositing a low dielectric constant amorphous carbon film on a substrate or other workpiece using high density plasma chemical vapor deposition (HDP-CVD) techniques. Specifically, the present invention provides a method for forming an amorphous carbon film having a low dielectric constant of less than about 3.0 and a high thermal stability at a temperature of at least about 400° C. In a preferred embodiment, the film is deposited using methane (CH₄) and argon in a HDP-CVD reactor. The amorphous carbon film formed according to the invention is useful for many applications in ultra large scale integration (ULSI) structures and devices, such as for example, an inter-metal dielectric material and an anti-reflective coating useful for patterning sub-micron interconnect features.

Claims

1. A method for forming an anti-reflective coating on a substrate, comprising:

a) positioning the substrate in a high density plasma chemical vapor deposition chamber;

b) introducing a processing gas comprising a hydrocarbon gas and a carrier gas into the chamber, wherein the hydrocarbon gas is selected from the group consisting of alkene hydrocarbons, alkane hydrocarbons, alkyne hydrocarbons, and combinations thereof;

c) generating a high density plasma of the processing gas;

d) depositing an amorphous carbon film on the substrate while maintaining the substrate at a temperature of about 300°

C. to 400°

C.; and

e) annealing the amorphous carbon film after deposition, wherein the amorphous carbon film is deposited on a dielectric layer of a substrate, a photoresistive layer is applied to the amorphous carbon film, and the dielectric layer is etched to form an interconnect structure.

2. The method of claim 1, further comprising:

maintaining chamber pressure between about 10 mTorr and about 100 mTorr.

3. The method of claim 2, wherein the chamber pressure is maintained at about 20 mTorr.

4. The method of claim 1, wherein the hydrocarbon gas is introduced between about 10 sccm and about 500 sccm and the carrier gas is introduced between about 5 sccm and about 300 sccm.

5. The method of claim 1, wherein the hydrocarbon gas is introduced at about 125 sccm and the carrier gas is introduced at about 27 sccm.

6. The method of claim 1, wherein the hydrocarbon gas and the carrier gas are introduced at a ratio of hydrocarbon:

carrier gas between about 2;

1 and about 5;

1.

7. The method of claim 1, wherein the plasma is generated by applying an RF power at between about 1000W and about 2000W.

8. The method of claim 1, wherein the plasma is generated by applying an RF power at about 2 MHz to the chamber at about 1000W.

9. The method of claim 1, wherein the hydrocarbon gas comprises methane.

10. The method of claim 1, wherein the hydrocarbon gas comprises a gas selected from the group consisting of CH₄, C₂H₂, C₂H₄, C₂H₆, C₃H₈, and combinations thereof.

11. The method of claim 1, wherein the carrier gas comprises argon.